Photomagnetic Imaging: A Novel Modality for Cancer Imaging In the last decades, variety of in vivo imaging modalities have been developed using a broad spectrum of technologies to obtain structural, functional, and molecular information about the tissue under investigation. As one of these modalities, optical imaging can provide functional information such as hemoglobin concentration and also visualize exogenous contrast agents as well as molecular and functional markers. Unfortunately, optical imaging suffers from low resolution due to highly scattering nature of the biological tissue. Although, there are new emerging modalities like photo-acoustic tomography that can provide higher resolution images, quantitative accuracy of the recovered parameters still remains as one of the main issues. One common weakness of all these available optical imaging techniques is that they are capable of acquiring data only from the boundary of the medium. To overcome this limitation, my main goal in this proposal is to develop an entirely new approach, Photo-magnetic imaging, which still uses laser light to heat the medium under investigation but employ MRI to obtain the temperature map of the tissue with high resolution. The MR temperature maps will further be converted into the optical absorption maps using proper modeling of light propagation and heat transfer in tissue. My hypothesis is that the photo-magnetic imaging technique will provide quantitatively more accurate and higher resolution images due to acquisition of data from the whole medium under investigation that improves the underdetermined condition of the inverse problem. This training proposal is geared toward the first in vivo feasibility studies of this nove imaging modality using small animals. If successful, the outcome will be the beginning of a new imaging modality. Due to the utilization of a clinical MR scanner, this technique will have immediate clinical translation potential.